During the manufacturing of profiled bodies, such as, for example, multi-disk supports of clutches, crown gears or similar workpieces with a cylindrical basic structure, high degrees of accuracy and precision are frequently required. In particular, the accuracy and surface quality are what matter.
The workpieces described are mass-produced articles which are produced in large piece numbers. In addition to the qualitative features, the costs and yield are therefore also important criteria in a production installation for workpieces of this type.
DE 25 49 230 A1 discloses a method with which parts, as have been described above, can be produced. This method is termed the “Grob method” in deforming technology and tool manufacturing spheres. In this method, with a relatively thin-walled, hollow workpiece, both an internal profile and an external profile can be produced. For this purpose, the blank is drawn onto an arbor corresponding to the internal profile. In this state, the workpiece undergoes a feed motion, in which it is displaced along its workpiece axis and is rotated about the workpiece axis. During this feed motion of the workpiece, the workpiece is worked from the outside by ring-like, profiled rolls, said rolls, matched to the division of the profile and the feed motion of the workpiece, carrying out sudden individual rolling operations in a rapid sequence. These individual rolling operations are carried out in the same direction of rotation, which primarily runs in the longitudinal direction of the profile. The individual rolling operations following one another in the same tooth space in the longitudinal direction of the profile overlap with regard to their engagement on the workpiece. The disadvantage of this Grob method is that it cannot be integrated into a machining line with further deformation operations. Mechanization in time with the other deformation stages is not possible.
An alternative method is described in DE 20 17 709 A1. A special rolling tool makes it possible to produce the workpiece from a blank with a smooth external contour by means of a press, with each stroke of the press forming a workpiece from a blank. During each stroke of the press, a rolling operation takes place, in which the profiled rollers press the desired external profile into the circumferential surface of the workpiece. In this case, the profiled rollers are arranged in a lower die along the circumference of the workpiece to be machined. If the workpiece is pressed between the rollers by means of an upper die, which is fastened to the ram of the press, said rollers are supported on supporting rollers with appropriate mounting.
The lower die can be constructed in a rotationally symmetrical manner, with the individual profiled rollers which produce the profile of the workpiece being distributed regularly and at a uniform angle with respect to one another along the circumference of the workpiece. As a consequence of this and as a consequence of the rotationally symmetrical distribution of forces which arises during a deforming operation, the individual grooves produced by the respective profiled rollers are practically identical to one another. In particular, a step-free external contour is achieved.
The disadvantage of this method is that, for example, during the rolling deformation of an external toothing, when the profiled roller is moved into the material, a zone is produced in which the tooth face is not completely formed. This effect is caused technologically and cannot be avoided even by changing process parameters.